title: Wireless enzyme sensor system for real-time monitoring of blood glucose levels in fish.
abstract: Periodic checks of fish health and the rapid detection of abnormalities are thus necessary at fish farms. Several studies indicate that blood glucose levels closely correlate to stress levels in fish and represent the state of respiratory or nutritional disturbance. We prepared a wireless enzyme sensor system to determine blood glucose levels in fish. It can be rapidly and conveniently monitored using the newly developed needle-type enzyme sensor, consisting of a Pt-Ir wire, Ag/AgCl paste, and glucose oxidase. To prevent the effects of interfering anionic species, such as uric acid and ascorbic acid, on the sensor response, the Pt-Ir electrode was coated with Nafion, and then glucose oxidase was immobilized on the coated electrode. The calibration curve of the glucose concentration was linear, from 0.18 to 144mg/dl, and the detection limit was 0.18mg/dl. The sensor was used to wirelessly monitor fish glucose levels. The sensor-calibrated glucose levels and actual blood glucose levels were in excellent agreement. The fluid of the inner sclera of the fish eyeball (EISF) was a suitable site for sensor implantation to obtain glucose sample. There was a close correlation between glucose concentrations in the EISF and those in the blood. Glucose concentrations in fish blood could be monitored in free-swimming fish in an aquarium for 3 days.
authors.affiliation: Department of Ocean Sciences, Faculty of Marine Science, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Endo
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yonemori
authors.forename: Kyoko
authors.initials: K
authors.lastname: Hibi
authors.forename: Huifeng
authors.initials: H
authors.lastname: Ren
authors.forename: Tetsuhito
authors.initials: T
authors.lastname: Hayashi
authors.forename: Wakako
authors.initials: W
authors.lastname: Tsugawa
authors.forename: Koji
authors.initials: K
authors.lastname: Sode
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D001774:Blood Chemical Analysis / Q000295:instrumentation / Q000379:methods; D001786:Blood Glucose / Q000032:analysis* / Q000737:chemistry; D003199:Computer Systems; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005399:Fishes / Q000378:metabolism*; D005949:Glucose Oxidase / Q000737:chemistry*; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013686:Telemetry / Q000295:instrumentation* / Q000379:methods
chemical_list: D001786:Blood Glucose; D005949:Glucose Oxidase